This invention relates to hexahydro-1-arylspiro[3H-oxazolo-[3,4-a]pyridine-3,4'-piperidine] compounds and acid addition salts thereof which can be used to treat depression. U.S. Pat. No. 3,959,475 to V. J. Bauer and R. W. Kosley, issued May 25, 1976, described 1,3-dihydrospiro(isobenzofurans) which have anti-depressant activity. U.S. Pat. No. 3,957,828 to V. J. Bauer and H. H. Ong, issued May 18, 1976, discloses 3-aminoalkyl-1,3-dihydro-3-phenylspiro(isobenzofurans) which possess tranquilizing properties. The synthesis of spirocyclic oxazolo[3,4-a]pyridines and pyrido [1,2-c]-[1,3]oxazines is described by V. P. Arya, et al., in the Indian J. of Chem. 14B, 777-779 (1976). The synthesis of spiro[isobenzofuran-1(3H),4'-piperidines] and spiro[isobenzofuran-1(3H)-3'-piperidines] is described by A. Marxer, et al., in the J. Org. Chem. 40. 1427-1433 (1975). The synthesis of spiro[isobenzofuran-1(3H),4'-piperidines] as potential central nervous system agents is also described by V. J. Bauer, et al., in J. Med. Chem. 19, 1315-1324 (1976). The synthesis of spiro[isobenzofuran-1(3H),4'-piperidine]-3-ones, spiro[isobenzofuran-1(3H),4'-piperidines] and spiro[isobenzotetrahydrothiophene-1(3H)-4'-piperidines] is described by W. E. Parham, et al., in the J. Org. Chem. 41, 2628-2633 (1976).